<?php
/**
 * Created by PhpStorm.
 * User: 554665488
 * Date: 2018-6-20
 * Time: 9:15
 * @description:
 * @Author: yfl
 * @QQ 554665488
 */

$a = 'abcdpp';
//var_dump(isset($a{5}));
if (isset($a{5})) { //长度大于5返回true   小于5返回false
    echo '检测长度';
}